General practically used picture frame devices do not have any space for containing any other exhibitable sheets than the exhibit. So, it is practiced to keep those other exhibitable sheets behind the exhibit in layers, but many exhibitable sheets cannot be contained in this way.
There are also picture frame devices with a space for containing other exhibitable sheets than the exhibit, but most of them simply has a separate detachable container behind them. So, it is troublesome to take out the other exhibitable sheets than the exhibit for exchanging the exhibit or confirming those exhibitable sheets.
Furthermore, there is a picture frame device with an exhibit and a transparent resin sheet overlapped on a back sheet made of foam styrene surrounded on the four sides by U-shaped framing straight members connected by joints at the butt corners. The frame device allows the exhibit to be taken in and out by removing only one of the framing straight members, but if other exhibitable sheets than the exhibit are contained in layers as described above, it is troublesome to confirm the other exhibitable sheets.
If these other exhibitable sheets than the exhibit such as pictures and testimonials are kept in a cylindrical container, they are kept curled and must be straightened when exhibited.